Methyl chloroacetate synthesis system

Abstract

This invention relates to a methyl chloroacetate synthesis system, belonging to the technical field of chemical production. The methyl chloroacetate synthesis includes an esterification tower, which comprises a tower body A. The top of tower body A has a first discharge point connected to a phase separator via a pipe A. A first condenser is mounted on pipe A. The bottom of tower body A has a second discharge point connected to the inlet of a first reboiler via a pipe. The middle section of tower body A is an esterification zone, and the outer wall of the middle section of tower body A has a first feed point and a second feed point communicating with the esterification zone. This invention has the following advantages: the methyl chloroacetate synthesis system of this invention achieves methyl chloroacetate production at a relatively low cost, reducing methyl chloroacetic acid consumption and improving product quality and yield.

Description

Technical Field

[0001] This invention relates to a methyl chloroacetate synthesis system, belonging to the technical field of chemical production. Background Technology

[0002] Methyl chloroacetate is an organic compound with the chemical formula C3H5ClO2. It is a colorless and transparent liquid, slightly soluble in water, and miscible with ethanol, ether, acetone, and benzene. It is mainly used as an intermediate in organic synthesis, in the preparation of the insecticide dimethoate, and can also be used as a solvent.

[0003] In traditional workshops, the production of methyl chloroacetate involves the addition of raw materials such as methanol and chloroacetic acid during esterification. During distillation, the esters, water, alcohols, acids, and other materials in the reaction vessel form an azeotropic phenomenon. For example, in patent application number CN201410342356.3, the patent title is: A method for producing methyl chloroacetate. Its specific content includes: a gas-liquid-solid three-phase reaction using chloroacetic acid and methanol as raw materials and acidic resin as catalyst. The characteristic is that a modified acidic resin is used as catalyst, and a fixed-bed reactor can be used to complete the process. The process does not require the addition of a water-carrying agent. The steps include: (1) chloroacetic acid and methanol are mixed evenly in a certain proportion; (2) a fixed-bed reactor is filled with catalyst in an amount that is 2 / 3 of the reactor volume; (3) the reaction temperature is controlled at 80-120℃ and the space velocity is 0.5-2g raw material / catalyst.h; (4) continuous feeding is carried out using a feed pump; (5) the gas phase reaction product comes out at the top of the reactor and the product is collected. The aforementioned patent discloses a method for producing methyl chloroacetate through a gas-liquid-solid three-phase reaction using chloroacetic acid and methanol as raw materials and an acidic resin as a catalyst.

[0004] The following defects can be observed during use:

[0005] Methanol, a basic production raw material, is widely known to be a highly volatile gas with a flash point of approximately 11°C. It is extremely flammable, and its vapor mixed with air forms a mixture prone to explosion. If a leak encounters an open flame, the high heat can cause combustion and explosion. Therefore, if a leak is not handled promptly, it will have a significant impact on people and surrounding facilities, causing minor injuries and equipment damage, or even serious casualties and production shutdowns with potentially disastrous consequences.

[0006] Chloroacetic acid is a highly corrosive material, flammable when exposed to open flames or high heat. It decomposes under high heat, producing toxic and corrosive fumes. When exposed to moisture, it is highly corrosive to most metals. It is corrosive and irritating, and can cause burns. Inhalation of high concentrations of its vapor or skin contact with its solution can lead to rapid and significant absorption, causing acute poisoning. Therefore, if a leak is not handled promptly, it will have a significant impact on people and surrounding facilities, causing minor injuries and equipment damage, or even serious casualties and production shutdowns with potentially disastrous consequences. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: to solve one of the above problems, to provide a methyl chloroacetate synthesis system, which can predict and decisively pre-treat leakage accidents, thereby reducing the hazard level of leakage accidents.

[0008] The methyl chloroacetate synthesis of the present invention is characterized by: an esterification tower comprising a tower body A, wherein the top of the tower body A has a first discharge point connected to a phase separator via a pipe A, a first condenser is mounted on the pipe A, and the bottom of the tower body A has a second discharge point connected to the inlet of a first reboiler via a pipe. The middle section of the tower body A is an esterification zone, and the outer wall of the middle section of the tower body A has a first feed point and a second feed point connected to the esterification zone. The first feed point and the second feed point are spaced apart from top to bottom and are respectively connected to the chloroacetic acid outlet and the methanol outlet of the chloroacetic acid and methanol storage tanks. The top of the phase separator is connected to the esterification tower. The feed pipe has an aqueous phase outlet on the side wall of the phase separator body, and a heavy component crude ester outlet at the bottom of the phase separator body. The aqueous phase outlet is connected to a distributor via a pipe, and the heavy component crude ester outlet is connected to a dehydration tower via a pipe. The dehydration tower includes a tower body B, with a feed inlet in the middle of tower body B connected to the heavy component crude ester outlet via a pipe. The top of tower body B has a third discharge point, which is connected to a recovery tower via pipe B. Pipe B has a second condenser. The bottom of tower body B has a fourth discharge point, which is connected to a methyl chloroacetate storage tank via a pipe. The top distilled water outlet of the recovery tower is connected to the second feed point at the bottom of the esterification tower via a pipe exhaust branch C. Pipe exhaust branch C has a third condenser.

[0009] Furthermore, the outlet one of the splitter is connected to the third feed point at the top of the esterification tower via a pipeline, and the outlet two of the splitter is connected to the recovery tower via a pipeline. The distilled water outlet at the top of the recovery tower is connected to the second feed point of the tower body A via a pipeline exhaust branch C.

[0010] Furthermore, the chloroacetic acid and methanol storage tanks provide chloroacetic acid and methanol to the esterification tower, and the feeds are separate. After the distillate from the top of the esterification tower is condensed, it separates into layers in the phase separator. The aqueous phase is partially returned to the top of the esterification tower through the splitter for recycling, while the other part of the aqueous phase enters the recovery tower. The crude ester at the bottom of the phase separator enters the dehydration tower. The high-purity methyl chloroacetate obtained from the dehydration tower is stored in the methyl chloroacetate storage tank. After the distillate from the top of the dehydration tower is condensed, it enters the recovery tower. The distilled water outlet at the top of the recovery tower is connected to the second feed point of the tower body A through the exhaust branch pipe C for recycling. Wastewater is discharged from the bottom of the recovery tower.

[0011] Furthermore, the chloroacetic acid and methanol storage tank includes a first chloroacetic acid raw material tank and a second chloroacetic acid raw material tank arranged adjacent to each other. The bottoms of the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank are connected by a connecting pipe A. An electric valve A is installed on the connecting pipe A. The tank also includes a chloroacetic acid discharge main pipe. One end of the chloroacetic acid discharge main pipe is connected to the bottoms of the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank through chloroacetic acid discharge branch pipes A and B, respectively. The other end of the chloroacetic acid discharge main pipe is connected to a first inlet point. The chloroacetic acid discharge main pipe also has a circulating pump A for chloroacetic acid transportation. The chloroacetic acid discharge branch pipes A and B are respectively equipped with… The system includes an electric valve extraction branch pipe C and an electric valve D, as well as a first methanol feedstock tank and a second methanol feedstock tank arranged adjacent to each other. The bottoms of the first methanol feedstock tank and the second methanol feedstock tank are connected by a connecting pipe B, on which an electric valve B is installed. The system also includes a methanol discharge main pipe, one end of which is connected to the bottoms of the first methanol feedstock tank and the second methanol feedstock tank respectively through methanol discharge branch pipes A and B. The other end of the methanol discharge main pipe is connected to a second inlet point. The methanol discharge main pipe also has a circulating pump B for transporting chloroacetic acid. Electric valves E and F are respectively installed on methanol discharge branch pipes A and B.

[0012] Furthermore, the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank have the same diameter, both 3-8 meters, and the distance between the center lines of the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank is 10 meters, and a partition wall is installed between them.

[0013] Furthermore, the first methanol feedstock tank and the second methanol feedstock tank have the same diameter, both 3-8 meters, and the distance between the center lines of the first methanol feedstock tank and the second methanol feedstock tank is 10 meters, with a partition wall between them.

[0014] Furthermore, it also includes extraction branch pipes A, B, C, and D connected to the first chloroacetic acid raw material tank, the second chloroacetic acid raw material tank, the first methanol raw material tank, and the second methanol raw material tank. The other ends of extraction branch pipes A, B, C, and D are all connected to the vacuum station through the main extraction pipe.

[0015] Furthermore, the vacuum station includes a first water ring vacuum pump and a second water ring vacuum pump connected to the main exhaust pipe. The exhaust ports of the first and second water ring vacuum pumps are connected to a gas-water separator. The drain port of the gas-water separator is connected to a circulating water treatment device. The drain port of the circulating water treatment device is connected to a clear water tank. The clear water tank is connected to the water supply pipes of the first and second water ring vacuum pumps. The clear water tank also has a water supply pipe with a water supply pump. Water from an external water source is pumped into the clear water tank through the water supply pump and the water supply pipe. The exhaust gas from the first and second water ring vacuum pumps is separated into gas and water by the gas-water separator. The gas is discharged into the atmosphere, and the water is recycled and treated by the circulating water treatment device. The treated water is discharged into the clear water tank for reuse by the first and second water ring vacuum pumps. The clear water tank also has a water supply pipe for external water replenishment.

[0016] Furthermore, a vacuum storage tank is connected to the main extraction pipe, and electric valves M, N, X, and Y are respectively installed on extraction branch pipes A, B, C, and D. The system also includes a first camera system for monitoring the external walls of the first and second chloroacetic acid raw material tanks, and a second camera system for monitoring the leakage status of the external walls of the first and second methanol raw material tanks. A third camera system is installed inside each of the first, second, and first methanol raw material tanks. The system includes a first liquid level sensor, a second liquid level sensor, a third liquid level sensor, a fourth liquid level sensor, electric valves M, N, X, and Y, a first water ring vacuum pump, a second water ring vacuum pump, electric valves A, C, D, B, E, and F, all of which are electrically connected to the signal output terminal of the controller. The first liquid level sensor, the second liquid level sensor, the third liquid level sensor, the fourth liquid level sensor, the first camera system, and the second camera system are all electrically connected to the signal input terminal of the controller.

[0017] A methyl chloroacetate synthesis system, characterized by the following leakage handling process:

[0018] Step A: The chloroacetic acid and methanol storage tanks supply chloroacetic acid and methanol to the esterification tower, with separate feeds. The distillate from the top of the esterification tower condenses and separates into layers in the phase separator. A portion of the aqueous phase is returned to the top of the esterification tower via a splitter for reuse, while the remaining aqueous phase enters the recovery tower. The crude ester at the bottom of the phase separator enters the dehydration tower, where high-purity methyl chloroacetate is obtained and stored in the methyl chloroacetate storage tank. The distillate from the top of the dehydration tower condenses and enters the recovery tower. The distilled water outlet at the top of the recovery tower is connected to the second feed point of tower A via a pipe exhaust branch C for reuse. Wastewater is discharged from the bottom of the recovery tower.

[0019] Step B: If any one of the first, second, third, and fourth level sensors detects an abnormal rate of liquid level drop, the controller will then use the first and second camera systems to capture images of the outer walls of the first chloroacetic acid raw material tank, the second chloroacetic acid raw material tank, the first methanol raw material tank, and the second methanol raw material tank, respectively. If the leaking tank is determined to be the first chloroacetic acid raw material tank;

[0020] Step C: Close the corresponding electric valves C, D, E, and F;

[0021] Step D: Open the corresponding electric valve A;

[0022] Step E: Electric valves M, N, X, and Y are all normally closed. Open electric valve N.

[0023] Step E: The chloroacetic acid in the first chloroacetic acid raw material tank enters the second chloroacetic acid raw material tank through the connecting pipe A until the chloroacetic acid in the first chloroacetic acid raw material tank is completely drawn into the second chloroacetic acid raw material tank. Then, the connecting pipe A is closed, and the first water ring vacuum pump and the second water ring vacuum pump are shut down, thereby solving the problem of a major accident caused by leakage from the first chloroacetic acid raw material tank.

[0024] Furthermore, the sensor detected an abnormal liquid level drop rate specifically when the discharge volume of circulation pump A was less than the liquid level drop volume of the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank, or when the discharge volume of circulation pump B was less than the liquid level drop volume of the first methanol raw material tank and the second methanol raw material tank. Flow meter A and flow meter B are respectively installed at the outlets of circulation pump A and circulation pump B, and both flow meter A and flow meter B are connected to the controller.

[0025] Furthermore, the filling volume of the raw materials in the first chloroacetic acid raw material tank, the second chloroacetic acid raw material tank, the first methanol raw material tank, and the second methanol raw material tank is half of the corresponding tank volume.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The methyl chloroacetate synthesis system of the present invention achieves methyl chloroacetate production at a relatively low cost, reducing chloroacetic acid consumption and improving product quality and yield.

[0028] The methyl chloroacetate synthesis system of the present invention can detect an abnormal drop in liquid level rate by any one of the first, second, third, and fourth liquid level sensors. Then, the controller uses the first and second camera systems to capture images of the outer walls of the first chloroacetic acid raw material tank, the second chloroacetic acid raw material tank, the first methanol raw material tank, and the second methanol raw material tank, respectively, to ensure continuous long-term monitoring of production.

[0029] The methyl chloroacetate synthesis system of this invention, if the leaking tank is determined to be the first chloroacetic acid raw material tank; Step C: Close the corresponding electric valves C, D, E, and F; Step D: Open the corresponding electric valve A; Step E: Electric valves M, N, X, and Y are all normally closed, and electric valve N is opened; Step E: Chloroacetic acid in the first chloroacetic acid raw material tank enters the second chloroacetic acid raw material tank through the connecting pipe A until the chloroacetic acid in the first chloroacetic acid raw material tank is completely absorbed into the second chloroacetic acid raw material tank, and then the connecting pipe A is closed, thereby solving the problem of major accidents caused by leakage from the first chloroacetic acid raw material tank. After a leakage accident occurs, it can quickly respond and control the situation, reducing the severity of the leakage accident. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0031] Figure 1 This is a system diagram of the present invention;

[0032] Figure 2 This is a partial structural diagram of the present invention. Figure 1 ;

[0033] Figure 3 This is a partial structural diagram of the present invention. Figure 2 .

[0034] In the diagram: 1. Esterification tower; 2. Phase separator; 3. Dehydration tower; 4. Recovery tower; 5. Flow divider; 6. Methyl chloroacetate storage tank; 7. Chloroacetic acid and methanol storage tanks; 7.1. First chloroacetic acid feed tank; 7.2. Second chloroacetic acid feed tank; 7.3. Connecting pipe A; 7.4. Electric valve A; 7.5. Chloroacetic acid discharge main pipe; 7.6. Chloroacetic acid discharge branch pipe A; 7.7. Chloroacetic acid discharge branch pipe B; 7.8. Circulation pump A; 7.9. Electric valve C; 7.10. Electric valve D; 8. First reboiler; 9. First condenser; 10. Vacuum station; 11. First methanol feed tank; 12. Second methanol feed tank; 13. Connecting pipe B; 14. Electric valve B; 15. Methanol discharge main pipe; 16. Methanol discharge branch pipe A; 17. Methanol discharge branch pipe B; 18. Circulation pump B; 19. Electric valve E; 20. Electric valve F; 21. Extraction branch pipe A; 22. Extraction branch pipe B. 23. Suction branch pipe C 24. Suction branch pipe D 25. Suction main pipe 26. First water ring vacuum pump 27. Second water ring vacuum pump 28. Clean water tank 29. Gas-water separator 30. Circulating water treatment device 31. Water supply pump 32. Water replenishment pipe 33. Vacuum storage tank 34. First liquid level sensor 35. Second liquid level sensor 36. Third liquid level sensor 37. Fourth liquid level sensor 38. First camera system 39. Second camera system Detailed Implementation

[0035] The present invention will now be further described with reference to the accompanying drawings:

[0036] The present invention will be further illustrated by specific embodiments below, but it is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0037] Example 1

[0038] like Figure 1-3As shown, a methyl chloroacetate synthesis system includes an esterification tower 1, which comprises a tower body A. The top of tower body A has a first discharge point connected to a phase separator 2 via a pipe A. A first condenser 9 is mounted on pipe A. The bottom of tower body A has a second discharge point connected to the inlet of a first reboiler 8 via a pipe. The middle section of tower body A is an esterification zone. The outer wall of the middle section of tower body A has a first feed point and a second feed point connected to the esterification zone. The first and second feed points are spaced apart from top to bottom and are respectively connected to the chloroacetic acid outlet and methanol outlet of a chloroacetic acid and methanol storage tank 7. The top of the phase separator 2 has a feed line connected to the esterification tower 1. The separator body has an aqueous phase outlet on its side wall and a heavy component crude ester outlet at its bottom. The aqueous phase outlet is connected to a distributor 5 via a pipe, and the heavy component crude ester outlet is connected to a dehydration tower 3 via a pipe. The dehydration tower 3 includes a tower body B. The feed inlet in the middle of the tower body B is connected to the heavy component crude ester outlet via a pipe. The top of the tower body B has a third discharge point, which is connected to a recovery tower 4 via a pipe B. A second condenser is provided on the pipe B. The bottom of the tower body B has a fourth discharge point, which is connected to a methyl chloroacetate storage tank 6 via a pipe. The top distilled water outlet of the recovery tower 4 is connected to the second feed point at the bottom of the esterification tower 1 via a pipe exhaust branch C. A third condenser is provided on the pipe exhaust branch C.

[0039] Preferably, the outlet of the splitter 5 is connected to the third feed point at the top of the esterification tower 1 via a pipeline, and the outlet of the splitter 5 is connected to the recovery tower 4 via a pipeline. The distilled water outlet at the top of the recovery tower 4 is connected to the second feed point of the tower body A via a gas extraction branch pipe C.

[0040] Preferably, the chloroacetic acid and methanol storage tank 7 provides chloroacetic acid and methanol to the esterification tower 1 and feeds them separately. After the distillate from the top of the esterification tower 1 is condensed, it is separated into layers in the phase separator 2. The aqueous phase is partially returned to the top of the esterification tower 1 through the splitter 5 for recycling and reuse, while the other part of the aqueous phase enters the recovery tower 4. The crude ester at the bottom of the phase separator 2 enters the dehydration tower 3. The high-purity methyl chloroacetate obtained from the dehydration tower 3 is stored in the methyl chloroacetate storage tank 6. After the distillate from the top of the dehydration tower 3 is condensed, it enters the recovery tower 4. The distilled water outlet at the top of the recovery tower 4 is connected to the second feed point of the tower body A through the exhaust branch pipe C for recycling and reuse. Wastewater is discharged from the bottom of the recovery tower 4.

[0041] Example 2 is a further improvement on Example 1, differing from Example 1 in that: the chloroacetic acid and methanol storage tank 7 includes a first chloroacetic acid raw material tank 7.1 and a second chloroacetic acid raw material tank 7.2 arranged adjacent to each other. The bottoms of the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2 are connected by a connecting pipe A7.3. An electric valve A7.4 is installed on the connecting pipe A7.3. It also includes a chloroacetic acid discharge main pipe 7.5. One end of the chloroacetic acid discharge main pipe 7.5 is connected to the bottoms of the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2 through chloroacetic acid discharge branch pipes A7.6 and B7.7, respectively. The other end of the chloroacetic acid discharge main pipe 7.5 is connected to a first inlet point. The chloroacetic acid discharge main pipe 7.5 also has a circulating pump A7.8 for chloroacetic acid transportation. The chloroacetic acid discharge branch pipe A7.8... 6. The chloroacetic acid discharge branch pipe B7.7 is equipped with an electric valve extraction branch pipe C23 and an electric valve D7.10, respectively. It also includes a first methanol raw material tank 11 and a second methanol raw material tank 12 arranged adjacent to each other. The bottoms of the first methanol raw material tank 11 and the second methanol raw material tank 12 are connected by a connecting pipe B13. An electric valve B14 is installed on the connecting pipe B13. It also includes a methanol discharge main pipe 15. One end of the methanol discharge main pipe 15 is connected to the bottom of the first methanol raw material tank 11 and the second methanol raw material tank 12 through methanol discharge branch pipes A16 and B17, respectively. The other end of the methanol discharge main pipe 15 is connected to a second feed point. The methanol discharge main pipe 15 also has a circulation pump B18 for chloroacetic acid transportation. An electric valve E19 and an electric valve F20 are respectively installed on the methanol discharge branch pipes A16 and B17.

[0042] Preferably, the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2 have the same diameter, both 3-8 meters, and the distance between the center lines of the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2 is 10 meters, and a partition wall is provided between them.

[0043] Preferably, the first methanol feedstock tank 11 and the second methanol feedstock tank 12 have the same diameter, both 3-8 meters, and the distance between the center lines of the first methanol feedstock tank 11 and the second methanol feedstock tank 12 is 10 meters, and a partition wall is provided between them.

[0044] Preferably, it also includes extraction branch pipes A21, B22, C23 and D24 connected to the first chloroacetic acid raw material tank 7.1, the second chloroacetic acid raw material tank 7.2, the first methanol raw material tank 11 and the second methanol raw material tank 12. The other end of extraction branch pipes A21, B22, C23 and D24 are all connected to the vacuum station through the main extraction pipe 25.

[0045] Preferably, the vacuum station includes a first water ring vacuum pump 26 and a second water ring vacuum pump 27 connected to the main suction pipe 25. The exhaust ports of the first water ring vacuum pump 26 and the second water ring vacuum pump 27 are connected to a gas-liquid separator 29. The drain port of the gas-liquid separator 29 is connected to a circulating water treatment device 30. The drain port of the circulating water treatment device 30 is connected to a clean water tank 28. The clean water tank 28 is connected to the water supply pipes of the first water ring vacuum pump 26 and the second water ring vacuum pump 27. The clean water tank 28 also has a water replenishment pipe. 32. The water supply pipe 32 is equipped with a water supply pump 31. Water from an external water source is pumped into the clean water tank 28 through the water supply pump 31 and the water supply pipe 32. The exhaust gas from the first water ring vacuum pump 26 and the second water ring vacuum pump 27 is separated into gas and water by the gas-water separator 29. The gas is discharged into the atmosphere, and the water is recycled and treated by the circulating water treatment device 30. The treated water is discharged into the clean water tank 28 for recycling and reuse by the first water ring vacuum pump 26 and the second water ring vacuum pump 27. At the same time, the clean water tank 28 is also equipped with a water supply pipe 32, which can be replenished with water from the outside.

[0046] Preferably, a vacuum storage tank 33 is also connected to the main extraction pipe 25. Electric valves M, N, X, and Y are respectively installed on the extraction branch pipes A21, B22, C23, and D24. The system also includes a first camera system 38 for monitoring the external walls of the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2, and a second camera system 39 for monitoring the leakage status of the external walls of the first methanol raw material tank 11 and the second methanol raw material tank 12. A first liquid level indicator is installed in each of the first chloroacetic acid raw material tank 7.1, the second chloroacetic acid raw material tank 7.2, the first methanol raw material tank 11, and the second methanol raw material tank 12. Sensors 34, 35, 36, and 37, electric valves M, N, X, and Y, first water ring vacuum pump 26, second water ring vacuum pump 27, electric valves A7.4, C7.9, D7.10, B14, E19, and F20 are all electrically connected to the signal output terminal of the controller. The first liquid level sensor 34, 35, 36, 37, first camera system 38, and second camera system 39 are all electrically connected to the signal input terminal of the controller.

[0047] Example 3

[0048] A methyl chloroacetate synthesis system, with the following leakage handling procedure:

[0049] Step A: Chloroacetic acid and methanol storage tank 7 provides chloroacetic acid and methanol to esterification tower 1, with separate feeds. After condensation, the distillate from the top of esterification tower 1 separates into layers in phase separator 2. The aqueous phase is partially returned to the top of esterification tower 1 via splitter 5 for recycling, while the other portion enters recovery tower 4. The crude ester from the bottom of phase separator 2 enters dehydration tower 3. High-purity methyl chloroacetate obtained from dehydration tower 3 is stored in methyl chloroacetate storage tank 6. After condensation, the distillate from the top of dehydration tower 3 enters recovery tower 4. The distilled water outlet at the top of recovery tower 4 is connected to the second feed point of tower body A via a pipe exhaust branch C for recycling. Wastewater is discharged from the bottom of recovery tower 4.

[0050] Step B: If any one of the first liquid level sensor 34, the second liquid level sensor 35, the third liquid level sensor 36, and the fourth liquid level sensor 37 detects an abnormal rate of liquid level drop, the controller then uses the first camera system 38 and the second camera system 39 to capture images of the outer walls of the first chloroacetic acid raw material tank 7.1, the second chloroacetic acid raw material tank 7.2, the first methanol raw material tank 11, and the second methanol raw material tank 12, respectively. If it is determined that the leaking tank is the first chloroacetic acid raw material tank 7.1;

[0051] Step C: Close the corresponding electric valves C7.9, D7.10, E19 and F20;

[0052] Step D: Open the corresponding electric valve A7.4;

[0053] Step E: Electric valves M, N, X, and Y are all normally closed. Open electric valve N.

[0054] Step E: The chloroacetic acid in the first chloroacetic acid raw material tank 7.1 enters the second chloroacetic acid raw material tank 7.2 through the connecting pipe A7.3 until the chloroacetic acid in the first chloroacetic acid raw material tank 7.1 is completely absorbed into the second chloroacetic acid raw material tank 7.2, and then the connecting pipe A7.3 is closed, thereby solving the problem of a major accident caused by the leakage of the first chloroacetic acid raw material tank 7.1.

[0055] Preferably, the sensor detects an abnormal liquid level drop rate specifically when the discharge volume of circulation pump A7.8 is less than the liquid level drop volume of the first chloroacetic acid raw material tank 7.1 and the second chloroacetic acid raw material tank 7.2, or when the discharge volume of circulation pump B18 is less than the liquid level drop volume of the first methanol raw material tank 11 and the second methanol raw material tank 12. Flow meter A and flow meter B are respectively installed at the outlets of circulation pump A7.8 and circulation pump B18, and both flow meter A and flow meter B are connected to the controller.

[0056] Preferably, the filling amount of raw materials in the first chloroacetic acid raw material tank 7.1, the second chloroacetic acid raw material tank 7.2, the first methanol raw material tank 11, and the second methanol raw material tank 12 is half of the corresponding tank volume.

[0057] The methyl chloroacetate synthesis system of the present invention achieves methyl chloroacetate production at a relatively low cost, reducing chloroacetic acid consumption and improving product quality and yield.

[0058] The methyl chloroacetate synthesis system of the present invention can detect an abnormal drop in liquid level rate by any one of the first, second, third, and fourth liquid level sensors. Then, the controller uses the first and second camera systems to capture images of the outer walls of the first chloroacetic acid raw material tank, the second chloroacetic acid raw material tank, the first methanol raw material tank, and the second methanol raw material tank, respectively, to ensure continuous long-term monitoring of production.

[0059] The methyl chloroacetate synthesis system of this invention, if the leaking tank is determined to be the first chloroacetic acid raw material tank; Step C: Close the corresponding electric valves C, D, E, and F; Step D: Open the corresponding electric valve A; Step E: Electric valves M, N, X, and Y are all normally closed, open electric valve N; Step E: Chloroacetic acid in the first chloroacetic acid raw material tank enters the second chloroacetic acid raw material tank through the connecting pipe A until the chloroacetic acid in the first chloroacetic acid raw material tank is completely absorbed into the second chloroacetic acid raw material tank, and then the connecting pipe A is closed, and the first water ring vacuum pump and the second water ring vacuum pump are shut down, thereby solving the problem of major accidents caused by leakage of the first chloroacetic acid raw material tank. After a leakage accident occurs, it can quickly respond and control, reducing the hazard level of the leakage accident.

[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A methyl chloroacetate synthesis system, characterized in that: The column includes an esterification tower, comprising a column body A. The top of column body A has a first discharge point connected to a phase separator via a pipe A. A first condenser is mounted on pipe A. The bottom of column body A has a second discharge point connected to the inlet of a first reboiler via a pipe. The middle section of column body A is an esterification zone. The outer wall of the middle section of column body A has a first feed point and a second feed point connected to the esterification zone. The first feed point and the second feed point are spaced apart from top to bottom. The separation point is connected to the chloroacetic acid outlet and methanol outlet of the chloroacetic acid and methanol storage tanks, respectively. The top of the phase separator is equipped with a feed pipe connected to the esterification tower. The side wall of the phase separator body has an aqueous phase outlet, and the bottom of the phase separator body has a heavy component crude ester outlet. The aqueous phase outlet is connected to a distributor via a pipe, and the heavy component crude ester outlet is connected to a dehydration tower via a pipe. The dehydration tower includes a tower body B. The feed inlet in the middle of tower body B is connected to the heavy component crude ester outlet via a pipe. The top of tower body B has a third discharge point, which is connected to a recovery tower via pipe B. Pipeline B has a second condenser, and the bottom of tower B has a fourth discharge point, which is connected to a methyl chloroacetate storage tank via a pipeline. The top distilled water outlet of the recovery tower is connected to the second feed point at the bottom of the esterification tower via a pipe exhaust branch C. Pipe exhaust branch C has a third condenser. The outlet one of the distributor is connected to the third feed point at the top of the esterification tower via a pipeline, and the outlet two of the distributor is connected to the recovery tower via a pipeline. The top distilled water outlet of the recovery tower is connected to the second feed point of tower A via a pipe exhaust branch C. Next, the chloroacetic acid and methanol storage tanks provide chloroacetic acid and methanol to the esterification tower, and the feeds are separate. After the distillate from the top of the esterification tower is condensed, it separates into layers in the phase separator. The aqueous phase is partially returned to the top of the esterification tower through the splitter for recycling, while the other part of the aqueous phase enters the recovery tower. The crude ester at the bottom of the phase separator enters the dehydration tower. The high-purity methyl chloroacetate obtained from the dehydration tower is stored in the methyl chloroacetate storage tank. After the distillate from the top of the dehydration tower is condensed, it enters the recovery tower. The distilled water outlet at the top of the recovery tower is connected to the second feed point of tower body A through the exhaust branch pipe C for recycling. Wastewater is discharged from the bottom of the recovery tower.

2. The methyl chloroacetate synthesis system according to claim 1, characterized in that, The chloroacetic acid storage tank includes a first chloroacetic acid raw material tank and a second chloroacetic acid raw material tank arranged adjacent to each other. The first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank have the same diameter, which is 3-8 meters. The distance between the center lines of the first chloroacetic acid raw material tank and the second chloroacetic acid raw material tank is 10 meters, and a partition wall is installed between them.

3. The methyl chloroacetate synthesis system according to claim 2, characterized in that, The methanol storage tank includes a first methanol feedstock tank and a second methanol feedstock tank arranged adjacent to each other. The first methanol feedstock tank and the second methanol feedstock tank have the same diameter, which is 3-8 meters. The distance between the center lines of the first methanol feedstock tank and the second methanol feedstock tank is 10 meters, and a partition wall is installed between them.

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